Desdemona's father, Brabantio, is a rich and important Venetian politician. He likes Othello and invites him to visit his house a lot—but he never expected Othello to "steal" his daughter. Furthermore, he never believed his darling little girl would marry Othello unless she was drugged or under some kind of spell.
So we know he's a) a misogynist who thinks that women are objects that can be stolen and b) a racist. Chaming guy.
Like many Shakespearean fathers (think Baptista Minola from The Taming of the Shrew or Portia's dad, who arranges his daughter's marriage from his grave in The Merchant of Venice), Brabantio tends to see his daughter as his property, which means that he sees marriage as a potential business transaction.
Brabantio's irrational fears about his daughter's interracial marriage make him a central figure in the play's examination of race and sex (which you can read more about in our "Themes" section). Check out this quote:
Look to her, Moor, if thou hast eyes to see.
She has deceived her father, and may thee. (1.3.333-334)
Wow: here Brabantio is equating "eloping to get married to a black man" to "cheating on her husband." It's a double whammy of sexism and racism.
Brabantio apparently dies of grief after his daughter runs off with Othello.
And you know what? We didn't even cry.